The present invention claims the priority of Taiwan Patent Application No. 89118070, filed on Apr. 9, 2000.
1. Field of the Invention
The present invention relates to a high-density functional slide and the preparation method thereof. More particularly, it relates to the application of a sol-gel containing amine-group bearing silanes and a solution containing polyaldehyde groups onto an organic or inorganic substrate, respectively, to form a high-density functional slide.
2. Description of the Related Art
There are many biomaterial immobilization methods that are available to immobilize biomaterial on different kinds of materials. For example, chemical activation, entrapment and crosslinking are well known in the art. However, these conventional methods suffer from many drawbacks, such as forming products of low stability and low activity and the inability of any one method to work well with a variety of biomaterial.
The conventional processes generally involve the treatment of a substrate surface with silanization, followed by the crosslinking reaction with biomaterials. In the silanization treatment, the surface of the substrate is activated based on its material, and then treated by a hydrophilic silane such as aminopropyltriethoxysilane (APTES). Afterwards, the crosslinking reaction is performed via a crosslinker such as glutaldehyde to immobilize biomaterials on the substrate. The shortcomings of the processes are long reaction time required for each of the steps (e.g. 4 hours or more), and low reaction efficiency. In addition, the homogeneity of the functional groups on the slide is uneven. This results in difficulties that the quality-control department has to overcome, and thus increases the production cost.
U.S. Pat. Nos. 5,919,626 and 5,922,534 disclose a method for attachment of unmodified nucleic acids to silanized solid phase surfaces. However, the surface of the solid phase is activated by a base, followed by bonding to epoxy-silane/amino-silane groups to facilitate the immobilization of nucleic acids/nucleotides. The disclosures of U.S. Pat. Nos. 5,563,056, 5,741,551, and 5,858,653 relate to the preparation of three dimensional, crosslinked matrices containing covalently immobilized chemical species and unbound releasable chemical species by photochemistry.
In the prior art, the co-deposition of silane and polyaldehyde groups onto a substrate in the sol-gel manner is not disclosed. Further, the application of the sol-gel onto an organic or inorganic substrate to form a high-density functional slide with an ultra-thin layer is also not disclosed.
It is therefore the primary object of the present invention to provide a method for preparing a high-density functional slide, comprising the steps of: (a) preparing a sol-gel of silanes in a first solvent; (b) coating said sol-gel onto a substrate; (c) removing the first solvent to form an interlayer on the surface of the substrate; (d) preparing a solution of polyaldehyde groups in a second solvent; (e) coating said solution onto the interlayer to form a polyaldehyde layer; and (f) removing the second solvent.
Another aspect of the present invention provides a high-density functional slide, comprising: (i) a substrate; (ii) an interlayer of a silane formed by coating a sol-gel of silanes onto said substrate; and (iii) a polyaldehyde layer formed onto said interlayer.
Still another aspect of the present invention provides a microarray having high-density functional groups for immobilization of a bio-molecule, comprising: (i) a substrate; (ii) an interlayer of a silane formed by coating a sol-gel of silanes onto said substrate; (iii) a polyaldehyde layer formed onto said interlayer; and (iv) a biologically active material, which is immobilized onto said polyaldehyde layer.
In one preferred embodiment of the present invention, the polyaldehyde polymer is prepared via the graft co-polymerization of polyvinylalcohol-based polyaldehyde. Therefore, the present invention also provides a polyvinylalcohol-based polyaldehyde graft copolymer, which is prepared by the following steps: (a) dissolving polyvinylalcohol in water to form a polymeric solution; (b) adding the monomer of allyl alcohol and acrolein to the polymeric solution under anaerobic conditions; and (c) adding ceric ammonium nitrate to the solution for catalysis.